I wouldn't use the term "hippies" in the way you used it. Older people during the war may have lumped the long-haired protesters together as "hippies," but the term would have sounded strange and out of touch for the protesters or for anyone, in general, under 30. Hippies were a specific group from a specific time. They were not political activists even if they advocated general social reform. For example, some of the protesters who demonstrated at the 1968 democratic convention called themselves "Yippies" as a way to make it clear that they were not part of the hippie movement even if they shared some of the general appearance and attitudes that dominated the generation. But I wouldn't use the term "Yippie" either since that lasted only a matter of weeks in the terminology of day. I would refer to the war protesters as "war protesters," many of whom were students and minorities.